1. Field of the Invention
The invention relates to novel therapeutic compositions for the treatment of oily skin and acne.
The disease of acne vulgaris is reported to be the single most common skin disease and affects approximately eighty percent of the teenage population. However, it may persist into the third and fourth decades of life. Acne primarily is a disease of the pilosebaceous system with a multifactorial cause. The pathogenesis includes an androgen dependent increase in sebum production, proliferation of the follicular microflora (principally P. acnes) and alteration in the follicular keratinization. This results in the primary clinical lesions of acne, namely the open comedone (blackheads), closed comedone (whiteheads), papules, pustules, and nodules. The increased sebum production is responsible for the oily appearance. Currently therapy is directed towards treatment of the lesions. The presence of oil itself is not the cause of acne but is a great psychological problem for the acne patient.
The onset of acne vulgaris is related to adolescence and normal sexual and physical growth. During this rapid linear growth period there is a marked development in the pilosebaceous system which results in sebum production and changes in its composition and physical characteristics. These events are hormonally controlled.
The disease of the pilosebaceous follicle is first detectable by change occurring in the follicular epithelium. The pilosebaceous unit is made up of a hair follicle and a pilosebaceous gland which are connected to the skin surface by ducts through which the hair passes. The sebaceous gland produces sebum which is a mixture of fats and waxes that transgress the duct and spread to the skin surface which helps keep the skin soft and moist. The acne lesion develops when the gland and lining begin to work excessively which predominantly occurs during puberty. The glands produce more sebum making the skin oily. The duct normally sheds cells which are carried to the skin surface by the sebum. When acne develops, cells stick together to form a thick layer and plug the duct. More cells and sebum pile up behind this plug which results in the primary lesion of acne, the comedone. If the plug stays below the skin surface, it is called a "closed comedone" or a "whitehead." A comedone which pushes through the surface is referred to as an "open comedone" or "blackhead." This is not due to dirt but due to discloration or melanin, the dark pigment in normal skin. The whiteheads and blackheads are referred to as "noninflammatory acne lesions." However, the pilosebaceous unit can rupture and become inflammed and these are the pimples, papules, and pustules which are the inflammatory lesions of this disease.
Pilosebaceous units are found all over the body, but they are more predominant on the face, chest, and the back. These are usually the predominant areas which develop acne.